A group including Goldman Sachs yesterday agreed to buy Associated British Ports - Britain's largest ports group and owner of the Hams Hall distribution complex near Coleshill - for £2.5 billion.

Admiral Acquisitions, a group including Goldman Sachs and investors from Singapore and Canada, offered 810 pence in cash for AB Ports after sweetening an offer made earlier in the year.

However, analysts and dealers said a rival bid could still emerge after AB Ports shares were bought above the agreed offer price in early trade. Dealers said Dresdner Kleinwort Wasserstein was buying about £100 million worth of stock.

"This may turn out a bit like P&O, where the bidders were leapfrogging each other. At this stage, there is one bidder on the table but there are a lot of rumours in the market," Oriel Securities analyst Gerald Khoo said.

However, AB Ports chief executive Bo Lerenius said the firm had not been approached by any other bidders. "We have had no discussions with anyone else," he added.

A source familiar with the situation said Dresdner was not buying shares on behalf of the Admiral group.

The deal followed a $6.8 billion (£3.71 billion) takeover of British ports operator P&O by Dubai Ports World, which was completed in March following a bidding war with Singapore's PSA International.

Goldman Sachs is under pressure to complete the deal following a string of failed bids, including airports group BAA, ITV and Birmingham-based pubs group Mitchells & Butlers.

A consortium led by Goldman Sachs last week lost out on a £10 billion offer for UK airports operator BAA to a rival consortium led by Spain's Ferrovial.

AB Ports said on May 23 it had opened its books to the Goldman Sachs consortium after receiving a revised 810p bid. AB Ports rejected a 730 pence bid earlier in the year.

Both companies said in a statement the offer was a premium of 16.4 per cent to AB Ports's share price on March 24, the last business day before news of a possible offer was announced.

Mr Lerenius said shareholders were "very happy" with the price and the new owners had no plans to change the company's management or strategy. However, he has yet to discuss his own future with the bidders.

AB Ports last month sold its entire operations in the United States for $107.8 million (£58.9 million) to focus on UK ports.

The Admiral consortium includes Canada's Borealis Infrastructure, which is the investment vehicle of Ontario pension fund OMERS; GIC Special Investments, the private equity arm of the Government of Singapore Investment Corporation and Infracapital Partners.

Port operators have become attractive targets due to their stable income streams and large property portfolios.

Analysts said potential bidders could include Australia's Macquarie Bank. They ruled out the likelihood of PSA making another play for a UK port as it would clash with Singapore's GIC.

Apart from the Admiral group, Mr Lerenius said the company had not received a takeover approach since 2000.